Hi, I can understand your concern for painful spots which have been red and irritated. It seems from your problem that you are suffering from the problem of folliculitis over the affected areas. Folliculitis is a common problem which arises due to blockage of pores of oil glands which are attached to the hair shaft. Due this blockage we feel the sensation of mild itching or tingling which may get converted into pain sensation. It is a common problem over friction prone areas. Once the folliculitis is healing it leaves behind the area as blackish crust or scab over the affected area. You need not to do anything for it actively as the scab will fall off by itself in few days of time. At the maximum you can do warm water compresses over the affected area.For the prevention of this situation in future kindly follow the suggestions below: -You should maintain good hygiene -Wear cotton clothes and cotton undergarments. -Keep your self away from hot and humid climate. - Take two times bath. You can meet a dermatologist for proper antibiotic therapy. All the best.